Printing cylinder clamp for tensioning flexible printing plates



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United States Patent 3,410,211 PRINTING CYLINDER CLAMP FOR TENSIONINGFLEXIBLE PRINTING PLATES Hans Griinig, Bern, Switzerland, assignor toMaschinenfabrik Winkler, Fallert & Co. A.G., Bern, Switzerland FiledOct. 8, 1965, Ser. No. 494,188 Claims priority, application Sweden, Oct.26, 1964, 12,889/64 14 Claims. (Cl. 101415.1)

ABSTRACT OF THE DISCLOSURE A device for fastening flexible printingplates within a recess formed in a printing cylinder includes agenerally C-shaped holding piece over which one end of the printingcylinder is directed and at least one rail member which has means forclamping the opposite end of the printing cylinder. The rail member isrotatable for the purpose of tensioning the printing plate and forengaging the first end with a spring clamping element to hold this firstend while the second end is being moved in a direction to tension theplate.

The clamping means includes two rail members which are arrangedend-to-end and which may be moved in axial directions toward and awayfrom each other to engage and disengage clutch elements defined on theseends for the purpose of providing combined or single movement of therail members. The arrangement permits the clamping of a single wideprinting plate or several narrow printing plates in a side-by-sidearrangement on the plate cylinder.

This invention raltes, in general, to the construction of printingcylinders and, in particular, to a new and useful printing platecylinder having means for securing various size flexible printing platesthereon, particularly for employment in rotary offset printing machines.

The present invention is an improvement over the prior art, particularlyin respect to the construction of clamping means which permit the easyinstallation of flexible printing plates and the securing of plates inposition by clamping means which is located in a recess within thecylinder. A particular advantage of the present construction is that theclamping means is adjustable to permit the mounting of either a singlewide or a plurality of narrow printing plates side by side on the platecylinder. In addition, the construction is such that it is possible tomount a plurality of narow printing plates individually andindependently of each other. It is also possible with the inventiveconstruction toeffect the tightening of the printing plates in a singlemanipulation, even though the plate may be very wide. The device alsopermits a very fine compass adjustment.

In accordance with the invention, the printing cylinder includes arecess with a relatively narrow opening gap on the cylindercircumference in which recess is positioned a clamping rail member. Therail member is adapted to be aflixed to one end of the printing plate tobe affixed to the plate cylinder and it may be rotated and shifted totension and to bias the printing plate and to tightly clamp the firstend thereof. In one embodiment of the invention two such rail membersare provided which are interengaged centrally but which may be rotatedtogether for the purpose of clamping an extremely wide printing plate tothe plate cylinder. The construction is such that the rail members whichclamp the ends of the printing plate may be moved simultaneously whenthey are engaged or independently when they are separated. Simple meansare provided for effecting their engagement or separation.

In still another embodiment of the invention the rail 3,410,211 PatentedNov. 12, 1968 members are constructed so that they do not engage so thatthey may be separately manipulated such as for clamping narrow printingplates on a printing cylinder. In a further modification only one railmember is provided which my be rotated for the purpose of automaticallyholding one end of the printing plate and engaging the other while theprinting plate is tightened around the cylinder.

Accordingly, it is an object of the invention to provide an improvedprinting cylinder construction having means within the cylinder forsimply and easily clamping a printing plate to the surface of thecylinder and requiring only a small cylinder surface gap.

A further object of the invention is to provide a print ing cylinderwith a clamp means which includes one or more rail members which areslidable and rotatably displaceable within said cylinder and withfurther means for adjusting the position of said rail members forclamping one end of a printing plate and thereafter holding the oppositeend while a printing plate is tightened on the printing cylinder.

A further object of the invention is to provide a printing cylinderwhich is simple in design, rugged in construction and economical tomanufacture.

For an understanding of the principles of the invention, reference ismade to the following description of typical embodiments thereof asillustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a partial section taken on the line 1 1 of FIG. 3;

FIG. 2 is a view similar to FIG. 1, but indicating the clamping means ina clamping position;

FIG. 3 is a longitudinal section of the printing cylinder constructed inaccordance with the invention;

FIG. 4 is a partial view similar to FIG. 3 indicating the slide rails inan uncoupled position;

FIG. 5 is a section taken along the line 55 of FIG. 3;

FIG. 6 is a partial section taken along the line 6-6 of FIG. 3;

FIGS. 7 and 8 are end elevational views of the two slide rails;

FIGS. 9 and 10 are side elevational views of the slide rails;

FIG. 11 is a partial sectional view taken along the line 1111 of FIG. 3;

FIG. 12 is a sectional view taken along the line 12-12 of FIG. 11;

FIG. 13 is a longitudinal sectional view of another embodiment of theinvention; and

FIG. 14 is a longitudinal sectional view of still a further embodimentof the invention.

Referring ot the drawings in particular, the invention embodied thereinin the embodiments of FIGS. 1 to 12 comprises a printing plate cylinder1 over the exterior surface of which is applied a flexible printingplate 2. As indicated in FIG. 1, one end 2a of the flexible printingplate 2 is directed around an end of a holding piece member 4 and anopposite end 2b is directed between clamping elements comprising a lugmember or lug plate 6 and a spring 7 which are held in a clampedposition by a clamping bar 24 which, in turn, is held against a face ofa slide rail member 14 by a threaded bolt 23. The holding piece 4 isrigidly connected to two slides 8 and 9 (FIGS. 3 and 4) which areprovided with bores 10 and 11 in which slide rails 14 and 15 arerotatably mounted by means of bushings 12 and 13. The holding piece 4includes a recess 16 in which a step-bearing 17 is secured by means of athreaded bolt member 18. The step-bearing 17 carries journals 19 and 20which engage a bore 21 and 22, respectively, of the slide rail members14 and 15 which are shown in elevation and side view in FIGS. 7 to 10.

As best indicated in FIGS. 1 and 2, the spring 7 serves to permit theintroduction of the plate end 2b between the lug plates 6. The plates 6include projections 28 which are engaged in a recess 27 of the sliderails 14 and 15. The clamping bar 24 is held to the slide rails by thebolt 23 and holds the end 2b of the printing plate 2 against the plates6. The upper end of the spring 7 engages the end 2a of the printingplate 2 and holds it against an inner face of the holding piece 4 whenthe rails 14 and and the slides 8 and 9 are moved in a manner to bedescribed more fully hereinafter to effect the clamping of the printingplate 2. The spring 7 thus prevents the end 2a from bending upwardly outof the recess formed by the holding piece 4.

Each of the slide rails 14 and 15 are provided with a recess 27 forreceiving a projection or lug formation 28 on the lug 6. An edge 29 ofthe slide rails 14 and 15 forms a fulcrum for the lug plates 6. Thefinal clamping position of the end 2b is indicated in FIG. 2.

Referring to FIG. 6, the means for orienting the rails 14 and 15 forclamping and unclamping purposes are shown which include wedges 30 and31 which are ins rted on each side of an associated slide 8 or 9 in arecess 38 defined in the printing cylinder 1. T he wedges 30 and 31 haveconical half-round faces 32 and 33 which cooperate with similar conicallateral faces 34 and 35 of the slides 8 and 9. The opposite straightfaces 36 and 37 of the wedges 30 and 31, respectively, bear against theside walls of the recess 38 and on the insert 39 in the cylinder 1. Thewedges 30 and 31 are provided with smooth bores 40 and 41, respectively,into which are inserted screws 42 and 43, respectively. The screwsextend through a ring 44 and are held to the ring by means of a securingpin or wedge 45. The extreme ends of the screws are threaded intothreaded bores 46 and 47 defined in the plate cylinder 1. Above theslides 8 and 9 are inserted holding pieces 48 with bores 49 and 50.Wrenches (not shown) are introduced through the bores 49 and 50 and intothe screws 42 and 43 for the purposes of threading and unthreading twoslides 8 and 9 are thus displaced irregularly to the left or the right,the holding elements comprising mainly the holding piece 4, the sliderails 14 and 15, and the slide bars 24 with the lug strip 6 and thespring 7, are displaced together away from the radial edge 51 of theplate cylinder 1 and toward the inclined edge 52. In this manner theprinting plate 2 may be aligned on the form cylinder 1. If the slides 8and 9 are displaced on both sides by the same amount, the device can beused in certain cases for an exact compass adjustment.

Means are provided for rotating the clamping device in addition to itslateral shifting adjustment. These means include a double lever memberhaving arms 53 and 54 as indicated in FIG. 11 with a hub portion whichengages the respective ends of the rails 14 and 15. The double levermember engages the respective rails through wedges 55 and 56 asindicated in FIG. 3. The wedges fit in recesses defined on therespective rails and double arm lever members. The opposite inner endsof the slide rails which are oriented in end-to-end relationship asindicated in FIG. 3, are provided with engaging claws 57, 58 and 59 and60. Axial displacement of the slide rail 15 is prevented by the coverdisc 61 and screw 62 (FIG. 3, left side). The other slide rail 14,however, is arranged for axial displacement in order to cause engagementof the two slide rails 14 and 15 by means of the claws 57, 58,

4 59 and 60 or to keep them disengaged as indicated in FIG. 4.

In order to displace the slide rail 14 axially a nut assembly 63 (FIG.3) is journalled in the double lever between the arms 53 and 54 andsecured by a disk 64. A threaded bolt 66 is connected with the nutassembly 63 by means of a pin 65, and its inner end is threaded into theslide rail 14. If only one wide printing plate is to be clamped on theplate cylinder 1, the two slide rails 14 and 15 are coupled by means ofa wrench (not represented) which is introduced into the hexagonal head67 of the nut assembly 63, as shown in FIG. 3. The Wide printing plateis then clamped by turning the two coupled slide rails 14 and 15. Thisis accomplished as indicated in FIGS. 11 and 12 by means which eifectsrotation of only one of the coupled slide rails 14 and 15. The clampingis effected uniformly and simultaneously over the entire width of theprinting plate. Deformation of the ends of the printing plate whichmight happen when clamping with separate slide rails is thus avoided. Ifnarrow printing plates are to be attached side by side, the slide rails14 and 15 must be disengaged, as indicated in FIG. 4, by turning theassembly nut 63 with the wrench so that each plate can be securedseparately.

The clamping mechanism indicated in FIGS. 11 and 12 includes the doublelevers 53 and 54 having rotary nut 68 into which are introduced threadedbolts 69 having a ring 70 whose threaded shaft is turned into thethreaded bore of the supporting bolt 71. The threaded bolt 69 isprovided with an inner hexagonal head 72. By means of a wrench (notrepresented) the threaded bolt 69 can be turned so that the doublelevers are rotated to elfect the tightening or loosening of the printingplates around the slide rails 14 and 15 which are rotated by thisaction. The lever arm 53 is biased in a clockwise direction, asindicated in FIG. 11, by means of a spring 76 which has one end pivotedto the arm at 73 and the opposite end anchored to a pivot point 74 onthe plate cylinder 1. A stop 77 limits the path of the double levers 53and 54. In order to prevent the threaded bolt 69 from turning out of thenut 68, a disk 81 is secured in the cover plate 79 by means of a screw80. The disk is provided with a bore 82 arranged above the innerhexagonal head 72 for access by a wrench element. The supporting bolt 71is rotatably mounted in the ring 83 and in the cover plate 79. The bolt69 is secured in the ring 83.

In the embodiment illustrated in FIG. 13, there is shown a platecylinder 1' which has displaceable slide rails 84 and 85 with nointerengaging claws which rotat on journals 19' and 20', respectively.In this embodiment only two narrow printing plates arranged side by sidemay be clamped over the printing cylinder 1. No mechanism is provided inthis embodiment for displacing the slide rails 84 and 85 axially. Theslide rails, however, are rotatable, and under the control of amechanism of a type indicated in FIGS. 11 and 12 for the purpose ofeffecting the clamping as in the other embodiment.

In FIG. 14, a further simplification is indicated in respect to aprinting cylinder 1 which includes a Single rail slide 86 which isrotatable as in the other embodiments under the influence of suitablecontrol mechanisms of the type indicated in FIGS. 11 and 12 but which isnot axially displaceable. The means for rotating the rail slide 86 forclamping purposes are advantageously located on a single slide.

All of the embodiments of the invention are featured by the fact thatthey require only a single elongated narrow slot defined in the printingcylinder 1 for receiving the end of printing plates 2. In addition, allof the constructions provide a simple means for clamping the printingplates 2 and-for effecting the accurate adjustment thereof by therotation of the rail members which effect the clamping.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise Without departing from such principles.

What is claimed is:

1. A printing device comprising a printing plate cylinder having arecess terminating exteriorly in a narrow slot on the periphery of saidprinting cylinder, a flexible printing plate extending around saidprinting cylinder and having respective first and second ends extendingthrough the slot and into the recess of said cylinder, and clampingmeans in said recess including a holding piece having a side face overwhich said first end of said printing plate is directed and a railmember having means for clamping and holding said second end, said railmember carrying a projecting clamping member, and means for displacingand rotating said rail member to engage said clamping member over saidfirst end of said printing plate on said holding piece side face and todisplace said second end in a direction to tension and position saidprinting plate in respect to said cylinder.

2. A printing device, according to claim 1, wherein said holding piececomprises a substantially C-shaped member having an interior edge overwhich said first end of said printing plate is directed, said railmember including means engageable with said first end of said printingplate to hold said end over said holding piece.

3. A printing device according to claim 1, including a clamping plate,and threaded bolt means for clamping said clamping plate to said railmember comprising said means for clamping said second end of saidprinting plate to said rail member.

4. A printing device according to claim 1, wherein Said rail member hasa recess thereon and a clamping lug comprising said clamping meanscarried on said rail member with a projection extending into saidrecess, said lug being pivotal with the lug engaged in the recess andsaid second end of said printing plate being directed over said lug andclamped to said rail member.

5. A printing device according to claim 1, including two separate railmembers which are arranged in axial relationship.

6. A printing device according to claim 1, including two separate railmembers arranged in axial end-to-end relationship and having claw meansthereon for permitting interengagement of said rail members to permitsimultaneous rotation thereof for clamping of said printing plate.

7. A printing device, according to claim 6, including means in therecess of said plate cylinder mounting said rail members for axialdisplacement toward and away from each other for engagement anddisengagement of said claw means.

8. A printing device according to claim 1, including a slide rotatablysupporting said rail member and wedge means engageable with said slidefor engaging said slide Within said cylinder for effecting displacementof the second end of said printing plate.

9. A printing device according to claim 1, including a slide rotatablysupporting said rail member, said slide carried in a recess of saidprinting cylinder, a wedge member disposed on each side of said slidewithin said recess and having wedging surfaces engageable with saidslide, and threaded bolt means holding said wedge members in position oneach side of said slide, said threaded bolt members permittingdisplacement of said wedge members and the shifting of said slide.

10. A printing device according to claim 9, including a cap covering therecess having said slide, said cap having access means for engaging saidthreaded bolt members from the exterior of said printing cylinder forthe purpose of shifting said wedge member.

11. A printing device comprising a printing plate cylinder having arecess terminating exteriorly in a narrow slot on the periphery of saidprinting cylinder, a flexible printing plate extending around saidprinting cylinder and having respective first and second ends extendingthrough the slot and into the recess of said cylinder, and clampingmeans in said recess including a holding piece for holding said firstend of said printing plate and a rail for clamping said second end,means for displacing and rotating said rail member to cause holding ofsaid first end of said printing plate by said holding piece as saidsecond end is displaced to tension and position said printing plate inrespect to said cylinder, a lug having a flat surface within the recessof said plate cylinder over which said second end of said printing plateis directed, said rail member having a recess therein, said lug having aprojection engaged in the recess of said rail member permitting pivotalmovement of said lug in respect to said rail member, a clamping barclamped to said rail member and clamping said second end of saidprinting plate thereto, and a spring member clamped by said clamping barand extending upwardly to engage said first end of said printing platewhen said rail member is moved to a clamping position.

12. A printing device comprising a printing plate cylinder having arecess terminating exteriorly in a narrow slot on the periphery of saidprinting cylinder, a flexible printing plate extending around saidprinting cylinder and having respective first and second ends extendingthrough the slot and into the recess of said cylinder, clamping means insaid recess including a holding piece for holding said first end of saidprinting plate and two rail members for clamping said second endarranged in axial end-toend relationship, means for displacing androtating said rail member to cause holding of said first end of saidprinting plate by said holding piece as said second end is displaced totension and position said printing plate in respect to said cylinder,claw means on adjacent ends of said rail members for permittinginterengagement of said rail members to permit simultaneous rotationthereof for clamping of said printing plate, said rail members beingaxially displaceable apart for disengagement of said claw means, and athreaded nut assembly rotatable at one end of said cylinder andthreadably engaged with at least one of said rail members for displacingsaid rail members axially upon rotation of said threaded nut member.

13. A printing device comprising a printing plate cylinder having arecess terminating exteriorly in a narrow slot on the periphery of saidprinting cylinder, at least one flexbile printing plate extending aroundsaid printing cylinder and having respective first and second endsextending through the slot and into the recess of said cylinder, aholding piece for holding said first end of said printing plate and atleast two rail members for clamping said second end, and means fordisplacing and rotating said rail member to cause holding of said firstend of said printing plate by said holding piece as said second end isdisplaced to tension and position said printing plate in respect to saidcylinder, said rail members being laterally displaceable forinterengagement and displacement separately and jointly rotatablyadjustable and laterally displaceable, and means mounting said railmembers for rotational movement in the recess of said plate cylinder andfor lateral movement together for engagement and joint rotationalmovement and apart for separate rotational movement.

14. A device for fastening flexible printing plates within a recess of aprinting cylinder which terminates in a slot on the periphery of saidprinting cylinder, comprising clamping means adapted to be positioned inthe recess for clamping each end of the printing plate including aholding plate for holding one end of the printing plate and at least twoclamping rails arranged end-to-end and each having means for clamping alength of the opposite end of said printing plate, means for mountingsaid rails in the printing cylinder recess for transverse and rotativemovement, adjacent ones of said clamping rails having adjacent ends withinterengageable portions, said clamp- References Cited UNITED STATESPATENTS 823,099 6/1906 Bechman 101378 1,650,206 11/1927 Halliwell101-378 1,901,076 3/1933 Bechman 101247 10 WILLIAM B. PENN,

Faeber 101415.1 Park et a1. 101-4151 Hantscho 101415.1 S'alubfirlich101-4151 Peabody et a1. 101415.1 Fischer 101415.1

Griinig 101415.1 Harenza 101415.1

Primary Examiner.

J. R. FISHER, Assistant Examiner.

